1. Field of the Invention
The present invention relates generally to base band voice telephony using derived voice over data technology. More specifically, systems and methods for providing base band voice telephony to a client premise using derived voice over data technology are disclosed.
2. Description of Related Art
Voice over asynchronous transfer mode (“VoATM”) technology (or voice over digital subscriber line technology, “VoDSL”) technology is increasingly being utilized to provide derived, multiple voice line capabilities over a digital subscriber line (“DSL”) operating over twisted pair copper phone lines. VoATM technology involves digital transmission of voice conversations over ATM networks while voice conversations are traditionally carried over base band analog phone lines. Typically, the VoATM process involves segmenting a stream of synchronous voice signals into cells, or packets, each with a header, and interleaving the cells into the ATM network with cells from other sources, and eventually delivering the cells to their respective destination where they are converted back into a synchronous data stream.
VoATM may be implemented over DSL utilizing any DSL technology. In particular, VoATM works particularly well for single-line or symmetric DSL (“SDSL”) loops using voice client or customer premise equipment (“CPE”) capable of providing multiple derived voice lines over a single DSL line. SDSL offers in a single 2-wire implementation and, currently, a symmetric data rate of up to 1.1 Mbps or 2.048 Mbps in light of recent improvements. Such CPEs may enable 16 or more telephone lines as well as high-speed data connection, such as Internet access, to be delivered over a single DSL connection. The CPE may provide a plurality of standard analog plain old telephone service (“POTS”) ports allowing connections for phone sets, facsimile machines, and modems. The derived voice lines optionally supports various features such as caller ID, call waiting, and messaging. The CPE may include a router to providing bridging and Internet protocol (“IP/IPX”) routing to support applications for high-speed data access such as to the Internet and/or a corporate network. FlowPoint™ 2200V Integrated Access Device (“IAD”) provided through FlowPoint Corporation (Los Gatos, Calif.) is an example of a CPE device suitable for providing digitized voice features and high-speed Internet and corporate data access over one SDSL.
In addition to SDSL, various other types of DSL technologies have been developed and utilized. One example is an asymmetrical DSL (“ADSL”) which can simultaneously transport high-bit-rate digital information towards the subscriber, lower rate data from the client, and analog voice all via a single twisted wire pair. Other technologies have been or are being developed which can similarly allow the simultaneously transmission of digital data signals and analog voice signals via a single twisted wire pair.
CPEs typically connect over ATM virtual circuits (“VCs”) to a voice gateway device, which may be common to a metropolitan area. Examples of virtual circuits include permanent virtual circuit (“PVC”), soft or smart PVC (“SPVC”), and switched virtual circuit (“SVC”). The voice gateway is capable of providing a standard interface to voice network devices or switches.
However, in order to provide telephone service to a client, a provider generally requires the client to subscribe to DSL data services and/or to have a VoATM CPE at the client premise. Such requirements increase the complexity and cost of subscribing to VoATM services, including voice telephone using derived voice over data technology. Thus, what is needed is a simpler and cost-effective system and method for utilizing derived voice over data technology, such as DSL and VoATM technologies, to provide voice telephony service to a client premise.